president's address. 29 



close-grained blue diorite, which is found so commonly in 

 dykes, under the united action of the sea and air between low 

 and high water marks. No doubt it spreads a little, but it 

 nevertheless remains strictly localised. Not so the yellow 

 clay. This may have originated in the decomposition of the 

 gneiss of the island, but it has been moved backwards and 

 forwards, or far enough to have its grains of quartz rounded, 

 and has, as I have said before, been deposited on a smoothed 

 rock. Not only this ; the agent which has deposited it has 

 acted with intermission, for the clay contains well marked 

 layers, such layers being formed by variations in the propor- 

 tions of the clay and sand. 



As the Society will remember, I stated in a paper read 

 in 1892,* that with the evidence then before me I felt all we 

 could do was to look upon the yellow clay as associated with 

 the cliff-heads and raised beaches, offering additional evidence 

 of a submergence. At the same time I mentioned the fact 

 that I had come to that conclusion with full knowledge that 

 the evidence against the association of the clay with a sub- 

 mergence was strong. Now I feel that there may be another 

 explanation which, in a few words, I shall state, but I wish to 

 be free and to leave you free to give full weight to any other 

 theory or evidence which may be advanced to account for the 

 clays. 



The conclusions as to submergence, resting on the evi- 

 dence of the raised beaches, are not affected ; this year's work 

 had added to the evidence and established the submergence 

 beyond doubt. To-night Mr. J. J. Carey tells us that he has 

 added another high level raised beach deposit to the list. 

 This occurs at l'Eree, opposite Lihou, and not far from the 

 cromlech, and is 52 feet above mean sea level. It, therefore, 

 belongs to the Capelles series of beaches. The proved asso- 

 ciation of the clays with the cliff-heads and the partial 

 stratification of the clays remains untouched, but the work of 

 the year has increased the number of ways by which we may 

 account for the clays, and it is, I think, no longer absolutely 

 needed to associate them with an actual submergence. The 

 action of water in their distribution and stratification cannot 

 be given up. and. is so evident that I think we may be excused 

 if we hesitate before separating them from the submergence 

 that we have other evidence of. 



The proofs of submergence are to be found in the sea- 

 washed rocks at elevations up to 76 feet above mean sea level j 

 in the beaches which exist in company with sea-worn rock up 

 * Transactions of the Guernsey Society of Natural Science for 1892, pp. 219-235. • 



